1. Field of the Invention
The invention is relative to internal combustion engines which are in present use for transportation, manufacturing, electrical power production, agriculture, forestry, lawn maintenance, and compressors in common use for applications including heating and air conditioning, refrigeration, and inflation.
Internal combustion engines currently used are of two basic designs: Otto cycle or Brayton cycle. Piston engines incorporate a sequential division of a 360 or 720 degree circle roughly segmented in four cycles or strokes. Brayton (turbine) engines perform the same cycles but are continuous in those cycles because of a constant pressure design.
The operation of reciprocating internal combustion engines follows this sequence: the intake stroke, comprising roughly one fourth of the rotation, permits the introduction of combustibles, i.e., fuel and air. The compression stroke, covering again roughly one fourth of the rotation, compresses the air, further atomizing the fuel and heating both to the point of ignition in the case of the diesel concept, or to the point readily ignitable by a device for ignition in the gas engine. The power cycle, covering once again roughly one fourth of the total rotation, is the point in time and revolution where mechanical parts are subjected to the thermodynamic force induced by the rapidly expanding gases. The fourth and last stroke, exhaust, is the sequence of the rotation that allows for the escape of burnt fuel vacating the cylinders thereby providing space and time for the intake cycle and subsequent repetition of the other cycles. Finally, in difference to whether the strokes described be of the two or four stroke design, they occur in either a 360 or 720 degree rotation respectively.
The relative efficiency comparison between the two and four stroke is dependant on not only the physical advantages of one compared to the other, but also some subjective concerns that could loosely be tied to efficiency. The four stroke's increased complexity and increased size and weight compared to its power output is detrimental and the requirement of operating on a relatively horizontal plane are somewhat offset by its comparative fuel efficiency, less pollution, and intended use of the engine. Obviously an engine that has a power impulse once every 360 degrees instead of 720 degrees will produce more power. However, due to a number of physical dictums, what would seem to be an apparent potential of doubling the power output is mitigated by several factors. Some of these are: a decrease in the available volume of the cylinder due to intake, exhaust, and transfer ports, an increase of frictional loses due to higher operating temperatures and the loss of some fuel to the exhaust port during the intake cycle. Subjectively, the efficiency of a two stroke is its relative lightness and its ability to operate in positions other than the horizontal.
2. Description of the Related Art
Engines using a crankshaft suffer first and foremost during the power stroke. At the point whereby the burning and rapidly expanding gases deliver their peak pressure the cyclic progression of the piston, articulated rod, and crank journal assembly is such that leverage imparted to the output shaft is relatively small. This is unavoidable due to the extreme rapidity of the detonation (on the order of 3/1000th of a second). By the time leverage increases the design dictates that the piston is pulled down the cylinder thus increasing the volume and subsequently reducing available thermodynamic pressure. Man or animal powered devices using the crankshaft principle are extremely efficient largely due to a constant pressure availability. Attempts to mitigate this dictate have thus far been at the cost of a considerable increase in complexity. Ref. classification 123/197.4 documents U.S. Pat. No. -2001/0017122A1 and U.S. Pat. No. -1,349,660. In the case of the first classification myriad rollers and guide pins are fixed to a rod that has to be forked and offset to accommodate the same and still maintain centering on the piston. These rollers and pins follow the contour of a very difficult to manufacture epitrochoidal drum that likely would encounter severe wear problems, sidereal movement, and flexing. In the second classification an elliptical contour to which a thrust pin is drivingly connected to an output shaft would suffer from severe wear as its function necessitates a 180 degree reversal between cycles. It is in fact, relatively simple, but would suffer from severe vibration resulting in a shorter operational life than the journals of a conventional crank shaft. Additionally, a second piston connected to this elliptical contour would require a cylinder or sleeve to reciprocate and a commensurate increase in complexity and lubrication requirements.